Thermoreversible Gelation Polymer (TGP) Hydrogel as a Degradable Scaffold for Bone Marrow Stromal Cell Transplantation

Abstract

Recent studies have indicated that bone marrow stromal cells (BMSCs) have the potential to improve neurologic function when transplanted into animal cerebral infarct models. However, it is still undetermined how the BMSCs should be transplanted to safely obtain the most efficient therapeutic benefits. Therefore, this study was carried out aiming to assess whether a thermoreversible gelation polymer (TGP) hydrogel would act as a noninvasive. valuable scaffold in BMSC transplantation for brain infarct. Mice were subjected to permanent middle cerebral artery occlusion. Vehicle, BMSC suspension, or a BMSC-TGP construct was transplanted onto the ipsilateral intact neocortex at 7 days after the insult. The TGP hydrogel completely disappeared and provoked no inflammation in the host brain. In the BMSC-TGP construct-treated mice, many transplanted cells were widely engrafted in the ipsilateral cerebrum, including the dorsal neocortex adjacent to the cerebral infarct. The number of these transplanted cells was significantly larger than that in the BMSC-treated mice; the majority of the cells were positive for both neuronal nuclear antigen (NeuN) and microtubule-associated protein 2 (MAP2) and morphologically simulated neurons. These findings suggest that the surgical transplantation of tissue-engineered BMSCs onto the intact neocortex enhances the engraftment of donor cells around a cerebral infarct. TGP hydrogel, because of its unique biochemical properties, could be a promising candidate as a valuable scaffold in BMSC transplantation for central nervous system disorders.